Storage bin with flow control sealing apparatus

ABSTRACT

Storage bin for receiving and dispensing a material such as asphalt mix. The storage bin has openings for receiving and discharging the material stored therein, and each of the openings is provided with flow control apparatus including a gate which selectively opens and closes the opening to control the discharge of material therethrough. A fluid impermeable sealing condition is maintained between the gate, when closed, and the interior of the storage bin by means of a seal which is positioned between the bin and the gate in surrounding relation with the discharge opening in the bin and which is selectively operable to undergo sealing engagement with the gate.

United States Patent Brock et al.

STORAGE BIN WITH FLOW CONTROL SEALING APPARATUS Inventors: James Donald Brock; Erbie Gail Mize, both of Chattanooga, Tenn.

Assignee: Astec Industries, Inc., Chattanooga,

Tenn.

Filed: Feb. 26, 1973 Appl. No.: 335,700

US. Cl. 222/504 Int. Cl B67d 5/34 Field of Search 222/504, 505, 542, 511,

222/512, 146 R, 146 HE; 251/172 References Cited UNITED STATES PATENTS 3,348,739 10/1967 Brock 222/146 R Primary Examiner-Stanley H. Tollberg Attorney, Agent, or FirmJones, Thomas & Askew [57] ABSTRACT Storage bin for receiving and dispensing a material such as asphalt mix. The storage bin has openings for receiving and discharging the material stored therein, and each of the openings is provided with flow control apparatus including a gate which selectively opens and closes the opening to control the discharge of material therethrough. A fluid impermeable sealing condition is maintained between the gate, when closed, and the interior of the storage bin by means of a seal which is positioned between the bin and the gate in surrounding relation with the discharge opening in the bin and which is selectively operable to undergo sealing engagement with the gate.

15 Claims, 4 Drawing Figures 1 PATENTEB SEP 1 01974 sum 2 BF 2 FLUID PRESSURE SOURCE STORAGE BIN WITH FLOW CONTROL SEALING APPARATUS This invention relates in general to storage bins and in particular to storage bins useful for receiving and storing a material such as hot asphalt mix.

Asphalt mix used for paving purposes includes a mixture of asphalt and various sizes of aggregate, and the asphalt mixture is typically prepared at an asphalt mix plant which is situated some distance away from the actual location to be paved with the asphalt mix. The asphalt mix is transported by trucks or other suitable vehicles from the asphalt plant to the location being paved. It is known in the art to equip an asphalt plant with a storage bin which receives the preparedasphalt mix for temporary storage and subsequent discharge into a truck or other form of conveyance.

Asphalt storage bins known to the prior art, especially those storage bins used for storing hot asphalt mix, frequently employ various expedients to maintain the hot asphalt mix at an elevated temperature. Such expedients include storage bins which are insulated and which are equipped with heaters to supply heat to the asphalt stored within the bin. Storage bins for hot asphalt are also known which substitute inert or nonoxidizing fluid for the air which would otherwise be present in the free space above the asphalt stored in the bin, since the exposure of air to the hot asphalt mix stored in the bin causes the asphalt mix to deteriorate as a result of oxidation. It is essential to the efiicient operation of an inert gas asphalt storage bin that the storage bin be maintained in a relatively fluid-tight condition at all times other than those times when a quantity of asphalt mix is actually being supplied to or discharged from the bin.

This requirement of maintaining a relatively fluidtight condition at the openings to the storage bin has been particularly troublesome with regard to the asphalt mix discharge opening and discharge control gate, which is typically located at the lowermost location on the bin to permit gravity discharge of the asphalt mix through the discharge opening when the discharge control gate is opened. This difflculty arises because the discharge opening must not only be provided with a gate which opens and closes the opening to permit the selective discharge of asphalt mix, but must also be provided with another selective closure device which, when closed, maintains the requisite fluid-tight seal between the discharge opening and the discharge control gate.

An example of a piror art storage bin is found in U.S. Pat. No. 3,532,252, where a discharge opening of a storage bin is provided with a pair of clam gates for controlling the discharge of asphalt mix stored within the bin. The discharge opening is additionally provided with a separate airlock door and sealing arrangement which is disposed below the clam gates and which is selectively opened and closed to maintain a fluid-tight seal around the clam gates as set forth more fully in that patent. The arrangement of claim gates and a separate airlock door positioned below the clam gates must be housed within an airtight sealing chamber, and the volume of this sealing chamber must also be connected to a source of inert or nonoxidizing fluid. Storage bins of the type requiring two separate gates or closures at the discharge opening have the additional disadvantage of being relatively expensive to manufacture and to maintain, and have the additional disadvantage of requiring extensive operational control mechanisms including interlocks and other circuitry necessary to coordinate the proper sequence of openings and closings for the asphalt discharge gate and the fluid sealing gate. Such interlocking control mechanisms and circuitry are necessary to permit the storage bin to be operated by relatively unskilled people.

Accordingly, it is an object of the present invention to provide an improved storage bin for receiving, storing, and discharging asphalt mix.

It is another object of the present invention to provide an asphalt mix storage bin including an improved discharge control apparatus. I

It is still another object of the present invention to provide a hot asphalt mix storage bin in which asphalt flow and also the maintenance of a fluid-tight atmosphere within the bin are accomplished with a single receiving or discharge gate mechanism.

Other objects and many of the attendant advantages of the present invention will be readily apparent from the following description of a disclosed embodiment as set forth herein, including the drawings in which:

FIG. 1 shows a partially sectioned elevation view of a storage bin according to the disclosed embodiment of thepresent invention; I

FIG. 2 shows an elevation section view of the discharge control gate of FIG. 1 in closed and sealed condition;

FIG. 3 shows the gate of FIG. 2 in opened condition; and

FIG. 4 shows a schematic view of control circuitry according to the disclosed embodiment of the present invention.

Stated in general terms, the storage bin of the present invention includes at least one material flow opening and a flow control means located adjacent the material flow opening and selectively movable to positions which respectively close and seal the opening and which permit materialflow through the opening. The flow control means includes a gate movably positioned with respect to the opening, and a sealing means mounted on the bin in surrounding relation with the material flow opening. The sealing means is selectively movable into sealing engagement with the closed gate. In a preferred form of the invention, the gate hasa surface which is selectively movable into closure relation with the material flow opening in the storage bin, and the sealing means is selectively movable into sealing relation with this surface.

The present invention is more particularly described with reference to a particular disclosed embodiment thereof, as shown in the Figures, including a storage bin indicated generally. at 10 and having an interior region 11 for receiving a quantity of material, such as hot asphalt mix, to be stored. The storage bin is provided with a material inletaperture 12, preferably at an uppermost location on the bin, and the inlet aperture is provided with an inlet flow control means shown generally at 13, and having the primary function of maintaining a fluid impermeable seal at the inlet aperture at all times when material is not actually being introduced into the interior region 11 through the inlet aperture.

The interior ll of the storage bin is connected to be supplied through the conduit 14 with a quantity of an appropriate inert gas from the inert gas supply 15. The

inert gas provided by the inert gas supply 15 may be.

any suitable gas which prevents or inhibits the oxidation of a hot asphalt mix contained in the interior region 11, as is known to those skilled in the art. The inert gas supply may be provided by any suitable apparatus such as a storage tank containing an appropriate gas, or may alternatively be provided by a recirculating system which converts oxygen-containing atmosphere withdrawn from the bin into an inert or nonoxidizing gas, although the exact nature and operation of the inert gas supply 15, per se, forms no part of the present invention. The conduit 14 preferably is connected to supply the inert gas into the uppermost portion of the interior region 1 1, and suitable baffles or other gas dis tributing devices may be employed within this interior region to promote the circulation of the inert gas throughout the region. The storage bin 10 may also be provided with suitable thermal insulation and with a source of heat, if desired, although such provisions form no part of the present invention and omitted from the present description for purposes of clarity.

The storage bin 10 is provided with an opening 20, preferably at the lowermost location in communication with the interior region 11, through which the material 23 in the bin can be discharged upon operation of the flow control means shown generally at 19. This flow control means 19 includes a discharge gate 21 having a closure surface 22 mounted on the storage bin to place the closure surface in closely proximate relation to the opening 20, as best seen in the gate-closed position depicted in FIG. 2, so that the closure surface is in sufflciently proximate relation with the opening to prevent any of the material 23 contained within the interior region 11 from exiting through the opening 20. The discharge gate 21 may advantageously be provided by a plate made of an appropriate material such as steel or the like and having a flat upper surface comprising the closure surface 22.

The discharge gate 21 is mounted for reciprocal motion as shown by the arrow 24 in FIG. 1, and this reciprocal motion is imparted to the gate by a suitable source of motive force such as the fluid-powered actuator 25. A fluid-powered actuator 25 may be operated by a suitable source of hydraulic or pneumatic pressure to drive an actuating member 26 which is interconnected with the discharge gate 21. It can be seen from FIG. 3 that discharge of a quantity of the material 23 from the storage bin 10 is accomplished by operating the actuator 25 to withdraw the discharge gate 21 in a lateral direction so that the closure surface 22 is withdrawn from closure relation with the opening 20 of the storage bin.

Although the closure relation maintained between the opening 20 of the storage bin and the closure surface 22 of the discharge gate 21 is sufficiently restrictive to prevent flow of the material 23 from the bin, it will be appreciated that practical limitations imposed by factors such as manufacturing techniques and reliability of operation prevent such closure relation from being sufficiently air-tight to prevent the unwanted passage of gaseous fluids through the opening 20. To prevent the oxygen-containing atmosphere surrounding the storage bin from entering the interior 11 through the opening 20 and causing deterioration of the hot asphalt mix contained therein, the flow control means 19 selectively maintains a fluid impermeable sealing condition with a seal assembly 30 which is mounted on the storage bin 10 in position between the discharge gate 21 and the storage bin and in surrounding relation with the opening 20. The seal assembly 30 is provided in the disclosed embodiment by an inflatable seal 31 having an annular configuration which completely surrounds the bin region 32 adjacent the opening 20. The inflatable seal 31 is positioned within a seal housing 33 which is secured in airtight relation to the storage bin 10, and a fluid supply conduit 34 extends through the seal housing into communication with the hollow interior of the inflatable seal. The inflatable seal 31 preferably is of the type having a sealing element such as the striker bead 35 disposed along the entire extent of the seal. in the absence of air or other fluid pressure applied to the interior of the inflatable seal 31, atmospheric pressure causes the inflatable seal to collapse to a deflated condition as shown in FIG. 3 whereat the striker bead 35 is withdrawn. When appropriate fluid pressure is applied to the interior of the inflatable seal 31 through the conduit 34, however, the seal expands upon inflation to displace the striker head 35 outwardly to the position shown in FIG. 2 whereat the striker bead is moved into sealing contact with the closure surface 22. The contact established between the annular striker bead 35, in fully surrounding relation with the bin opening 20, and the closure surface 22 completely seals the opening 20 and the interior region 11 from exposure to the atmosphere surrounding the bin. When it is desired to discharge a quantity of the material 23 from the bin, however, fluid pressure is allowed to escape from the interior of the inflatable seal 31 until the seal collapses as shown in HO. 3, whereupon the discharge gate 21 is withdrawn from discharge blocking relation by the actuator 25.

As is especially apparent in FIG. 2, only a relatively small volume 36 is entrapped between bin region 32, the inflated seal 31, and the closure surface 22 when the discharge gate is positioned to close the opening. This relatively small volume 36, which is made possible with a flow control means having sealing means disposed on the storage bin and positioned between the bin and the gate, has no more than nominal oxidizing effect on the contents of the sealed storage bin and so this volume does not need to be supplied with inert gas from the inert gas supply 15.

It is preferred to coordinate the operation of the seal assembly 30 and the discharge gate 21 so that the striker bead 35 (or the comparable sealing engagement surface of another type of seal) is not damaged by lateral movement of the discharge gate while the seal is extended in the sealing engagement poistion, An example of apparatus for accomplishing interrelated control of the actuator 25 and the inflatable seal 31 is schematically depicted in FIG. 4, where both the inflatable seal and the actuator are assumed to be selectively operable in response to fluid pressure applied from a fluid pressure source 40. Pressurized fluid from the source 40 is applied through a conduit 41 to a 2-way valve which is schematically represented at 42 and which is selectively operable to conduct fluid pressure either to a close port 43 or to an open port 44 of the valve. The valve 42, in the embodiment shown, is of the type which vents to atmosphere the port which is not connected through the valve to the conduit 41, and those skilled in the art will recognize that valves of this type are conventionally providedwith a control element in the form of a reciprocable spool member which is positioned either manually or by solenoid or other actuator device to accomplish the appropriate routing of fluid pressure.

The close' port 43 is connected by a conduit 45 to one side of a double-action cylinder which comprises the actuator 25, in the disclosed embodiment. This same port is also connected through the conduit 46 to a fluid valve 47 of the type which is normally closed and which becomes open in response to depression of the actuating control 48. The actuating control 48 of the valve 47 is positioned to be actuated to the open condition only in response to movement of the discharge gate 21 to a position completely closing the storage bin opening 20, as shown in FIGS. 1 and 4. The outlet of the valve 47 is connected to the fluid supply conduit 34 of the inflatable seal 31 and is also connected along a conduit 49 to provide operating control pressure to a valve 50 interposed in the conduit 51 between the open port 44 of the valve 42 and the other side of the actuator 25. The valve 50 is of the type which is normally open and which becomes closed in response to control pressure in the conduit 41 exceeding a certain predetermined level.

Considering the operation of the control mechanism depicted in FIG. 4, it is assumed that the control valve 42 has just been moved to the depicted position to establish fluid pressure communication between the source 40 and the close port 43. Pressurized fluid flows through the valve and the conduit 45 to enter the right-hand side of the actuator cylinder 25, moving the actuator piston and the actuating member 26 in a position to move the discharge gate 21 laterally toward closure relation with the opening in the storage bin. Fluid pressure is also applied at this time along the conduit 46 to the valve 47, which is presently closed. Accordingly, no fluid pressure is applied to the inflatable seal 31 and this seal remains in the withdrawn or nonsealing position depicted in FIG. 3. When the discharge gate 21 is flnally positioned by the actuator in closure relation with the opening 20, the actuating control 48 of the valve 47 is contacted by the discharge gate (or by a member 52 operatively connected with the discharge gate) and the valve 47 is opened to admit fluid pressure through the conduit 34 into the inflatable seal 31. The seal expands at this time to move the striker head 35 downwardly into sealing engagement with the closure surface 22 of the discharge gate 21, as depicted in FIG. 2. Fluid pressure is also applied through the valve 47 and the conduit 49 to cause closure of the previously-open valve 50. However, closure of the valve 50 produces no positive result at this time, since atmospheric venting of the left-hand side of the actuator cylinder 25 has been completed through the open port 44.

Assuming now that it is desired to withdraw a quantity of the material 23 from the storage bin 10, the valve 42 is operated to terminate fluid pressure communication with the close port 43 and to establish such communication with the open port 44. Fluid pressure is immediately applied from the source to the line 51, but is prevented by the now-closed valve 50 from being applied to the actuator cylinder 25. Since the close port 43 is now vented to atmosphere, the pressurized fluid previously within the inflatable seal 31 is allowed to vent to atmosphere through the valve 47 and the conduit 46. This reduction of fluid pressure in the inflatable seal 31 is communicated along the conduit 49 to the control mechanism of the valve 50, which is set to maintain the valve 50in closed condition until the fluid pressure within the inflatable seal 31 is reduced below the level which permits the inflatable seal to retract to the nonsealing position as shown in FIG. 3. When that pressure level is reached, the valve 50 is opened and fluid pressure is admitted along the conduit 51 to the left-hand side of the actuating cylinder 25, whereupon the discharge gate is withdrawn from closure relation with the bin opening 20. At that time, the discharge gate 21 and the inflatable seal 31 are in position as depicted in FIG. 3. The valve 47 becomes closed as soon as the discharge gate 21 commences its opening movement, but no consequence attaches to closure of the valve 47 at that time inasmuch as adequate venting of the pressure within the inflatable seal 31 has been completed.

When it is again desired to close the discharge gate 21, the valve 42 is again actuated to supply pressurized fluid to the close port 43. Fluid pressure previously applied to the left-hand side of the actuating cylinder 25 is allowed to vent through the open valve 50, the conduit 51, and the open port 44; and subsequent operation of the actuator piston 25, the discharge gate 21, and the inflatable seal 31 occurs as aforementioned.

The inlet flow control means 13 which closes and maintains a fluid impermeable seal at the inlet aperture 12 is substantially similar in structure and in operation to the flow control means 19, with the primary difference being that the inlet flow control means 19 does not control discharge and functions to keep the storage bin 10 sealed except when the bin is being filled with a quantity of material from suitable apparatus (not shown) such as a conveyor or the like. The inlet flow control means 13 includes a gate member which has a closure surface 61 and which is suitably mounted for reciprocal motion in response to selective operation of the inlet actuator 62. The inlet actuator 62 may be a fluid-powered actuator similar to the actuator 25.

A seal housing 63 is positioned on the storage bin 10 in surrounding relation with the inlet aperture 12, and an inflatable seal 64 is disposed within the seal housing. The inflatable seal 64 may be similar in construction and operation to the inflatable seal 31 associated with the lower flow control means 19, and it can be seen that this inflatable seal 64, when supplied with operating pressure through the fluid supply conduit 65, expands outwardly to place the striker bead 66 into sealing engagement with the closure surface 61 of the gate member 60.

The control circuitry required to coordinate the operation of the inlet actuator 62 and the inflatable seal 64 is not shown herein, since those skilled in the art will recognize that controls comparable to the control mechanism shown in FIG. 4 can be utilized to operate the inlet flow control means.

It can be seen from the foregoing disclosure of an embodiment of the present invention that there is provided a storage bin, especially suited for the storage of materials such as hotasphalt mix, in which a single closure and seal mechanism provides both positive control of the discharge of material from the storage bin and selective, fluid impermeable sealing of the discharge opening in the bin. The apparatus of the present invention also is readily susceptible to coordinated control operation with a relatively small and inexpensive amount of control circuitry.

It will be understood, of course, that the foregoing relates only to a preferred embodiment of the present invention and that numerous alterations and modifications may be made therein without departing from the spirit and scope of the invention as defined in the following claims.

What is claimed is:

l. A storage bin for storing an asphalt mix in a controlled atmospheric environment and selectively dispensing such asphalt mix, comprising:

storage means defining a substantially fluidimpermeable region for receiving and containing asphalt mix and including a discharge opening at a lower region on said storage means through which asphalt mix is discharged;

flow control means positioned in operative relation with said discharge opening and selectively operative to a first position whereat the discharge opening is unblocked to permit discharge of asphalt mix within the said region and to a second position whereat the discharge opening is blocked and sealed;

said flow control means including gate means selectively movable into and out of position blocking asphalt mix from being discharged through said discharge opening;

sealing means positioned between said storage means and said gate means and being selectively operative to establish gaseous fluid impermeable sealing be- 3 tween said storage means and said gate means in said discharge blocking position;

said sealing means being positioned in surrounding relation with said opening, said sealing means being selectively operative for displacement in a direction away from said storage bin and toward said gate means to establish said fluid impermeable sealing condition, and said sealing means being additionally selectively operative to move in a direction away from said gate means and toward said storage bin to terminate the sealing condition; and

motive means connected to said gate means and selectively operative to place said gate means either into or out of said discharge blocking position, said motive means being responsive to the position of said sealing means to move said gate means out of said discharge blocking position only when said sealing means is moved to terminate said sealing condition.

2. The storage bin as in claim 1, wherein:

said sealing means is positioned in fluid impermeable relation to said storage means and has a gate contact portion disposed in annular surrounding relation to said discharge opening;

said sealing means being selectively operable to move said gate contact portion into sealing contact with said gate means.

3. The storage bin as in claim 2, wherein said sealing means includes an inflatable member which is operable upon selective inflation to displace said gate contact portion outwardly from said storage means and into sealing contact with said gate means.

4. A storage bin as in claim 1, wherein said gate means is mounted in laterally movable relation to said discharge opening, and including motive means operatively connected to said gate means and selectively operative to move said gate means laterally relative to said discharge opening.

5. A storage bin as in claim 1, wherein said gate means is mounted in laterally movable relation to said discharge opening, and including motive means operatively connected to said gate means and selectively operative to move said gate means laterally to said unblocked position and to said blocked position relative to said discharge opening, said sealing means comprises resiliently deformable means positioned in closely proximate surrounding relation to said discharge opening and in spaced relation to said blocked position occupied by said gate means, and said sealing means having a gate contact portion operative by said resiliently deformable means to move into sealing contact with said gate means positioned in said blocked position.

6. A storage bin as in claim 5, wherein said resiliently deformable means includes a hollow region to receive operating fluid pressure and is inflatable in response to fluid pressure in said hollow region to move said gate contact portion into said sealing contact, and valve means connected to receive a source of pressurized fluid and selectively operative to admit pressurized fluid to said hollow region to control the inflation of said resiliently deformable means into and out of said sealing contact.

7. Storage bin for receiving and dispensing asphalt mix, comprising:

storage means having an interior region for receiving and containing asphalt mix;

said storage means having at least one material flow opening disposed at a lower region therein for gravity discharge of asphalt mix from the interior region of the storage means;

gate means defining a closure surface and selectively operative to dispose said closure surface in position blocking the gravity discharge of asphalt mix through said material flow opening;

seal means positioned between said storage means and said closure surface and selectively operative for movement into gaseous fluid sealing contact with said closure surface when in blocking position, whereby said gate means and said seal means cooperate to prevent discharge of asphalt mix and flow of gas through said opening; and

motive means connected to said gate means and selectively operative to move said gate means out of said discharge blocking position;

said motive means being responsive to operation of said seal means to move said gate means out of said discharge blocking position only if said seal means is not in said gaseous fluid sealing contact with said closure surface.

8. Apparatus as in claim 7, wherein said closure surface is larger than said material flow opening so that a portion of the closure surface surrounds the blocked material flow opening when the gate means is in said blocking position, and said seal means is mounted surrounding said material flow opening and is selectively operative for movement into said gaseous fluid sealing contact with said surrounding portion of the closure surface.

9. Apparatus as in claim 8, wherein said seal means includes inflatable means mounted in gaseous fluid sealing relation with said storage means surrounding said material flow opening and selectively operable for expansion outwardly of said storage means into said gaseous fluid sealing contact with said surrounding portion of the closure surface.

10. In an apparatus for storing and dispensing an asphalt aggregate material and including a storage bin and a material flow opening defined in the storage bin, the improved means for selectively sealing the material flow opening comprising gate means disposed for selectively blocking or unblocking the passage of asphalt aggregate material through the material flow opening, seal means positioned between the storage bin and said gate means, said seal means being in gaseous fluid impermeable relation with said storage bin and being selectively operative to establish gaseous fluid sealing with said gate means in said blocking position, and control means operatively interconnected with said seal means and said gate means to cause termination of said gaseous fluid sealing before allowing said gate means to unblock said material flow opening.

1 1. Apparatus as in claim 10, wherein said seal means includes a gate contacting portion selectively movable toward said gate means to establish said sealing.

12. Apparatus as in claim 10, wherein said seal means comprises inflatable seal means disposed on the storage bin in surrounding relation with the discharge opening and selectively operable to move away from the storage bin into sealing contact with said gate means.

13. A storage bin for storing an asphalt mix in a controlled atmospheric environment and selectively dispensing such asphalt mix, comprising:

storage means defining a substantially fluidimpermeable region for receiving and containing asphalt mix and including a discharge opening at a lower region on said storage means through which asphalt mix is discharged;

flow control means positioned in operative relation with said discharge opening and selectively operative to a first position whereat the discharge opening is unblocked to permit discharge of asphalt mix within the said region and to a second position whereat the discharge opening is blocked and sealed;

said flow control means including gate means selectively movable into and out of position blocking asphalt mix from being discharged through said discharge opening;

sealing means positioned between said storage means and said gate means and being selectively operative to establish gaseous fluid impermeable sealing between said storage means and said gate means in said discharge blocking position;

said gate means being mounted in laterally movable relation to said discharge opening, and including motive means operatively connected to said gate means and selectively operative to move said gate means laterally to said unblocked position and to said blocked position relative to said discharge opening, said sealing means comprising resiliently deformable means positioned in closely proximate surrounding relation to said discharge opening and in spaced relation to said blocked position occupied by said gate means, and said sealing means having a gate contact portion operative by said resiliently deformable means to move into sealing contact with said gate means positioned in said I blocked position;

said resiliently deformable means including a hollow region to receive operating fluid pressure and is inflatable in response to fluid pressure in said hollow region to move said gate contact portion into said sealing contact;

valve means connected to receive a source of pressurized fluid and selectively operative to admit pressurized fluid to said hollow region to control the inflation of said resiliently deformable means into and out of said sealing contact; and

said valve means being operative in response to said gate means being moved to said blocked position by said motive means to admit pressurized fluid to said inflatable resiliently deformable means.

14. A storage bin for storing an asphalt mix in a controlled atmospheric environment and selectively dispensing such asphalt mix, comprising:

storage means defining a substantially fluidimpermeable region for receiving and containing asphalt mix and including a discharge opening at a lower region on said storage means through which asphalt mix is discharged;

flow control means positioned in operative relation with said discharge opening and selectivelyv operative to a first position whereat the discharge opening is unblocked to permit discharge of asphalt mix within the said region and to a second position whereat the discharge opening is blocked and sealed;

said flow control means including gate means selectively movable into and out of position blocking asphalt mix from being discharged through said discharge opening;

sealing means positioned between said storage means and said gate means and being selectively operative to establish gaseous fluid impermeable sealing between said storage means and said gate means in said discharge blocking position;

said gate means being mounted in laterally movable relation to said discharge opening, and including motive means operatively connected to said gate means and selectively operative to move said gate means laterally to said unblocked position and to said blocked position relative to said discharge opening, said sealing means comprising resiliently deformable means positioned in closely proximate surrounding relation to said discharge opening and in spaced relation to said blocked position occupied by said gate means, and said sealing means having a gate contact portion operative by said resiliently deformable means to move into sealing contact with said gate means positioned in said blocked position;

said resiliently deformable means including a hollow region to receive operating fluid pressure and is inflatable in response to fluid pressure in said hollow region to move said gate contact portion into said sealing contact;

valve means connected to receive a source of pressurized fluid and selectively operative to admit pressurized fluid to said hollow region to control the inflation of said resiliently deformable means into and out of said sealing contact; and 7 control means operatively connected to control said selective operation of said motive means, said control means being connected to be responsive to the inflation condition of said resiliently deformable means to enable said motive means to move said gate means from said blocked position to said unblocked position only if said gate contact portion means is out of said sealing contact.

15. A storage bin for storing an asphalt mix in a controlled atmospheric environment and selectively dispensing such asphalt mix, comprising:

storage means defining a substantially fluidimpermeable region for receiving and containing asphalt mix and including a discharge opening at a lower region on said storage means through which asphalt mix is discharged;

flow control means positioned in operative relation with said discharge opening and selectively operative to a first position whereat the discharge opening is unblocked to permit discharge of asphalt mix within the said region and to a second position whereat the discharge opening is blocked and sealed;

said flow control means including gate means selectively movable into and out of position blocking asphalt mix from being discharged through said discharge opening;

sealing means positioned between said storage means and said gate means and being selectively operative to establish gaseous fluid impermeable sealing be tween said storage means and said gate means in said discharge blocking position;

said gate means being mounted in laterally movable relation to said discharge opening, and including motive means operatively connected to said gate means and selectively operative to move said gate means laterally to said unblocked position and to said blocked position relative to said discharge opening, said sealing means comprising resiliently deformable means positioned in closely proximate surrounding relation to said discharge opening and in spaced relation to said blocked position occupied by said gate means, and said sealing means having a gate contact portion operative by said resiliently deformable means to move into sealing contact with said gate means positioned in said blocked position;

said resiliently deformable means includes a hollow region to receive operating fluid pressure and is inflatable in response to fluid pressure in said hollow region to move said gate contact portion into said sealing contact;

valve means connected to receive a source of pressurized fluid and selectively operative to admit pressurized fluid to said hollow region to control the inflation of said resiliently deformable means into and out of said sealing contact;

said valve means being operative in response to movement of said gate means to said blocked position by said motive means to admit pressurized fluid to said inflatable resiliently deformable means; and

control means operatively connected to control said selective operation of said motive means, said control means being connected to be responsive to the inflation condition of said resiliently deformable means to enable movement of said discharge gate means from said blocked position to said unblocked position only if said resiliently deformable means has withdrawn said gate contact portion from said sealing contact. 

1. A storage bin for storing an asphalt mix in a controlled atmospheric environment and selectively dispensing such asphalt mix, comprising: storage means defining a substantially fluid-impermeable region for receiving and containing asphalt mix and including a discharge opening at a lower region on said storage means through which asphalt mix is discharged; flow control means positioned in operative relation with said discharge opening and selectively operative to a first position whereat the discharge opening is unblocked to permit discharge of asphalt mix within the said region and to a second position whereat the discharge opening is blocked and sealed; said flow control means including gate means selectively movable into and out of position blocking asphalt mix from being discharged through said discharge opening; sealing means positioned between said storage means and said gate means and being selectively operative to establish gaseous fluid impermeable sealing between said storage means and said gate means in said discharge blocking position; said sealing means being positioned in surrounding relation with said opening, said sealing means being selectively operative for displacement in a direction away from said storage bin and toward said gate means to establish said fluid impermeable sealing condition, and said sealing means being additionally selectively operative to move in a direction away from said gate means and toward said storage bin to terminate the sealing condition; and motive means conneCted to said gate means and selectively operative to place said gate means either into or out of said discharge blocking position, said motive means being responsive to the position of said sealing means to move said gate means out of said discharge blocking position only when said sealing means is moved to terminate said sealing condition.
 2. The storage bin as in claim 1, wherein: said sealing means is positioned in fluid impermeable relation to said storage means and has a gate contact portion disposed in annular surrounding relation to said discharge opening; said sealing means being selectively operable to move said gate contact portion into sealing contact with said gate means.
 3. The storage bin as in claim 2, wherein said sealing means includes an inflatable member which is operable upon selective inflation to displace said gate contact portion outwardly from said storage means and into sealing contact with said gate means.
 4. A storage bin as in claim 1, wherein said gate means is mounted in laterally movable relation to said discharge opening, and including motive means operatively connected to said gate means and selectively operative to move said gate means laterally relative to said discharge opening.
 5. A storage bin as in claim 1, wherein said gate means is mounted in laterally movable relation to said discharge opening, and including motive means operatively connected to said gate means and selectively operative to move said gate means laterally to said unblocked position and to said blocked position relative to said discharge opening, said sealing means comprises resiliently deformable means positioned in closely proximate surrounding relation to said discharge opening and in spaced relation to said blocked position occupied by said gate means, and said sealing means having a gate contact portion operative by said resiliently deformable means to move into sealing contact with said gate means positioned in said blocked position.
 6. A storage bin as in claim 5, wherein said resiliently deformable means includes a hollow region to receive operating fluid pressure and is inflatable in response to fluid pressure in said hollow region to move said gate contact portion into said sealing contact, and valve means connected to receive a source of pressurized fluid and selectively operative to admit pressurized fluid to said hollow region to control the inflation of said resiliently deformable means into and out of said sealing contact.
 7. Storage bin for receiving and dispensing asphalt mix, comprising: storage means having an interior region for receiving and containing asphalt mix; said storage means having at least one material flow opening disposed at a lower region therein for gravity discharge of asphalt mix from the interior region of the storage means; gate means defining a closure surface and selectively operative to dispose said closure surface in position blocking the gravity discharge of asphalt mix through said material flow opening; seal means positioned between said storage means and said closure surface and selectively operative for movement into gaseous fluid sealing contact with said closure surface when in blocking position, whereby said gate means and said seal means cooperate to prevent discharge of asphalt mix and flow of gas through said opening; and motive means connected to said gate means and selectively operative to move said gate means out of said discharge blocking position; said motive means being responsive to operation of said seal means to move said gate means out of said discharge blocking position only if said seal means is not in said gaseous fluid sealing contact with said closure surface.
 8. Apparatus as in claim 7, wherein said closure surface is larger than said material flow opening so that a portion of the closure surface surrounds the blocked material flow opening when the gate means is in said blocking position, and said seal means is mounted surroundIng said material flow opening and is selectively operative for movement into said gaseous fluid sealing contact with said surrounding portion of the closure surface.
 9. Apparatus as in claim 8, wherein said seal means includes inflatable means mounted in gaseous fluid sealing relation with said storage means surrounding said material flow opening and selectively operable for expansion outwardly of said storage means into said gaseous fluid sealing contact with said surrounding portion of the closure surface.
 10. In an apparatus for storing and dispensing an asphalt aggregate material and including a storage bin and a material flow opening defined in the storage bin, the improved means for selectively sealing the material flow opening comprising gate means disposed for selectively blocking or unblocking the passage of asphalt aggregate material through the material flow opening, seal means positioned between the storage bin and said gate means, said seal means being in gaseous fluid impermeable relation with said storage bin and being selectively operative to establish gaseous fluid sealing with said gate means in said blocking position, and control means operatively interconnected with said seal means and said gate means to cause termination of said gaseous fluid sealing before allowing said gate means to unblock said material flow opening.
 11. Apparatus as in claim 10, wherein said seal means includes a gate contacting portion selectively movable toward said gate means to establish said sealing.
 12. Apparatus as in claim 10, wherein said seal means comprises inflatable seal means disposed on the storage bin in surrounding relation with the discharge opening and selectively operable to move away from the storage bin into sealing contact with said gate means.
 13. A storage bin for storing an asphalt mix in a controlled atmospheric environment and selectively dispensing such asphalt mix, comprising: storage means defining a substantially fluid-impermeable region for receiving and containing asphalt mix and including a discharge opening at a lower region on said storage means through which asphalt mix is discharged; flow control means positioned in operative relation with said discharge opening and selectively operative to a first position whereat the discharge opening is unblocked to permit discharge of asphalt mix within the said region and to a second position whereat the discharge opening is blocked and sealed; said flow control means including gate means selectively movable into and out of position blocking asphalt mix from being discharged through said discharge opening; sealing means positioned between said storage means and said gate means and being selectively operative to establish gaseous fluid impermeable sealing between said storage means and said gate means in said discharge blocking position; said gate means being mounted in laterally movable relation to said discharge opening, and including motive means operatively connected to said gate means and selectively operative to move said gate means laterally to said unblocked position and to said blocked position relative to said discharge opening, said sealing means comprising resiliently deformable means positioned in closely proximate surrounding relation to said discharge opening and in spaced relation to said blocked position occupied by said gate means, and said sealing means having a gate contact portion operative by said resiliently deformable means to move into sealing contact with said gate means positioned in said blocked position; said resiliently deformable means including a hollow region to receive operating fluid pressure and is inflatable in response to fluid pressure in said hollow region to move said gate contact portion into said sealing contact; valve means connected to receive a source of pressurized fluid and selectively operative to admit pressurized fluid to said hollow region to control the inflation of said resiliently deformablE means into and out of said sealing contact; and said valve means being operative in response to said gate means being moved to said blocked position by said motive means to admit pressurized fluid to said inflatable resiliently deformable means.
 14. A storage bin for storing an asphalt mix in a controlled atmospheric environment and selectively dispensing such asphalt mix, comprising: storage means defining a substantially fluid-impermeable region for receiving and containing asphalt mix and including a discharge opening at a lower region on said storage means through which asphalt mix is discharged; flow control means positioned in operative relation with said discharge opening and selectively operative to a first position whereat the discharge opening is unblocked to permit discharge of asphalt mix within the said region and to a second position whereat the discharge opening is blocked and sealed; said flow control means including gate means selectively movable into and out of position blocking asphalt mix from being discharged through said discharge opening; sealing means positioned between said storage means and said gate means and being selectively operative to establish gaseous fluid impermeable sealing between said storage means and said gate means in said discharge blocking position; said gate means being mounted in laterally movable relation to said discharge opening, and including motive means operatively connected to said gate means and selectively operative to move said gate means laterally to said unblocked position and to said blocked position relative to said discharge opening, said sealing means comprising resiliently deformable means positioned in closely proximate surrounding relation to said discharge opening and in spaced relation to said blocked position occupied by said gate means, and said sealing means having a gate contact portion operative by said resiliently deformable means to move into sealing contact with said gate means positioned in said blocked position; said resiliently deformable means including a hollow region to receive operating fluid pressure and is inflatable in response to fluid pressure in said hollow region to move said gate contact portion into said sealing contact; valve means connected to receive a source of pressurized fluid and selectively operative to admit pressurized fluid to said hollow region to control the inflation of said resiliently deformable means into and out of said sealing contact; and control means operatively connected to control said selective operation of said motive means, said control means being connected to be responsive to the inflation condition of said resiliently deformable means to enable said motive means to move said gate means from said blocked position to said unblocked position only if said gate contact portion means is out of said sealing contact.
 15. A storage bin for storing an asphalt mix in a controlled atmospheric environment and selectively dispensing such asphalt mix, comprising: storage means defining a substantially fluid-impermeable region for receiving and containing asphalt mix and including a discharge opening at a lower region on said storage means through which asphalt mix is discharged; flow control means positioned in operative relation with said discharge opening and selectively operative to a first position whereat the discharge opening is unblocked to permit discharge of asphalt mix within the said region and to a second position whereat the discharge opening is blocked and sealed; said flow control means including gate means selectively movable into and out of position blocking asphalt mix from being discharged through said discharge opening; sealing means positioned between said storage means and said gate means and being selectively operative to establish gaseous fluid impermeable sealing between said storage means and said gate means in said discharge blocking position; said gate means being mouNted in laterally movable relation to said discharge opening, and including motive means operatively connected to said gate means and selectively operative to move said gate means laterally to said unblocked position and to said blocked position relative to said discharge opening, said sealing means comprising resiliently deformable means positioned in closely proximate surrounding relation to said discharge opening and in spaced relation to said blocked position occupied by said gate means, and said sealing means having a gate contact portion operative by said resiliently deformable means to move into sealing contact with said gate means positioned in said blocked position; said resiliently deformable means includes a hollow region to receive operating fluid pressure and is inflatable in response to fluid pressure in said hollow region to move said gate contact portion into said sealing contact; valve means connected to receive a source of pressurized fluid and selectively operative to admit pressurized fluid to said hollow region to control the inflation of said resiliently deformable means into and out of said sealing contact; said valve means being operative in response to movement of said gate means to said blocked position by said motive means to admit pressurized fluid to said inflatable resiliently deformable means; and control means operatively connected to control said selective operation of said motive means, said control means being connected to be responsive to the inflation condition of said resiliently deformable means to enable movement of said discharge gate means from said blocked position to said unblocked position only if said resiliently deformable means has withdrawn said gate contact portion from said sealing contact. 